Iterator and Generator

Iterator and Generator

Iterator and generator are two concepts that are commonly used programming concepts. Both iterator and generator are used to manage data structures. They are used to move through elements and extract data from various data structures.

Iterator

An iterator is a programming concept that is used to traverse through a collection of values or elements. An iterator is also known as a cursor, and it is used to retrieve elements from a collection in a sequential manner.

The iterator can be used with any built-in data structures in programming language such as lists, tuples, dictionaries and sets. Iteration refers to the process of getting access to each element of a list tuple, dictionary, or set.

Iterators are very useful in programming as they eliminate the need to know the internal structure of a data structure. They also make the code cleaner and more readable. In python, the inbuilt function iter() is used to create the traversal object.

The iterator provides two essential functions:

1. __iter__: It returns the iterator object itself.

2. __next__: It returns the next value in the sequence.

If there are no more elements in the sequence, it raises the StopIteration Exception.

Generator

A generator is a special type of iterator that is used to create a sequence of values. Unlike the iterator, a generator is used to produce values as they are required.

A generator function is a function that yields a value whenever the 'yield' keyword is called. A generator is a more efficient way of producing infinite sequences without requiring to store them in memory.

Generators can be used to create a sequence of numbers, time intervals, and sequences that require computations. Generators are defined using the 'yield' keyword, and the function is called to produce the result.

Generators can be used to produce infinite sequences that cannot be produced using an iterator. An example of a generator is as shown:

def simple_generator():
    yield 1
    yield 2
    yield 3

g = simple_generator()
print(next(g))
print(next(g))
print(next(g))

The above code produces the output:

1

2

3

Conclusion

Iterators and generators are two essential programming concepts that are used to manage data structures. Iterators are used to retrieve elements in a collection in a sequential manner, while generators produce a sequence of values as they are required.

Both iterators and generators enhance the readability and efficiency of code. They are used to manipulate and traverse through different data structures in the programming languages such as Python and Java.